For some reason this code was not implemented into my bbpress defauly bbpress.css file.
I am posting it so you guys can update it for future releases..

When posting an image to the forum your current css makes the image 100% width, so it does not break the forum layout. Unfortunately this does not keep the image proportional so the height stays the same. All you have to do is this.

Change

#bbpress-forums div.bbp-topic-content img,
#bbpress-forums div.bbp-reply-content img {
	max-width: 100%;

To

#bbpress-forums div.bbp-topic-content img,
#bbpress-forums div.bbp-reply-content img {
	max-width: 100%;
        height: auto;

[@robin-w Moderator 10 years, 9 months ago]

Thanks for pointing this out. I’ve raised a trac ticket

https://bbpress.trac.wordpress.org/ticket/2553

so a developer should pick this up at some stage

Thanks again